Who was named by Lenin as the leader in his will?

The correct choice is based on the historical context surrounding Lenin's leadership and his views on the future of the Soviet Union. In his political testament, often referred to as his "will," Lenin expressed his concerns about various leaders in the Communist Party and outlined his thoughts on leadership succession. While he acknowledged Trotsky's considerable capabilities and contributions to the revolution, he also raised serious concerns about some other leaders, particularly Stalin, suggesting that he might not be the right choice for leadership due to his personality and approach to power.

Trotsky was indeed the leader whom Lenin viewed favorably in many respects and was positioned as a significant figure in the party with responsibilities including leading the Red Army during the Russian Civil War. This context makes the selection of Trotsky as the lead figure in Lenin's will a reflection of the high regard in which Lenin held him, especially in terms of his theoretical contributions and organizational skills.

This insight into Lenin's thinking highlights the complex dynamics of power within the nascent Soviet state and sets the stage for the subsequent power struggle that emerged after Lenin’s death, culminating in differing interpretations of Marxism and communism as practiced by other leaders who followed.